Question: Khan.scratchpad.disable(); To move up to the maestro level in his piano school, Omar needs to master at least $157$ songs. Omar has already mastered $20$ songs. If Omar can master $9$ songs per month, what is the minimum number of months it will take him to move to the maestro level?
To solve this, let's set up an expression to show how many songs Omar will have mastered after each month. Number of songs mastered $=$ $ $ Months at school $\times$ Songs mastered per month $+$ Songs already mastered Since Omar Needs to have at least $157$ songs mastered to move to maestro level, we can set up an inequality to find the number of months needed. Number of songs mastered $\geq 157$ Months at school $\times$ Songs mastered per month $ +$ Songs already mastered $\geq 157$ We are solving for the months spent at school, so let the number of months be represented by the variable $x$ We can now plug in: $x \cdot 9 + 20 \geq 157$ $ x \cdot 9 \geq 157 - 20 $ $ x \cdot 9 \geq 137 $ $x \geq \dfrac{137}{9} \approx 15.22$ Since we only care about whole months that Omar has spent working, we round $15.22$ up to $16$ Omar must work for at least 16 months.